The African Fire-Atmosphere Research Initiative (AFARI) is a regional expansion and continuation of the Southern African Fire-Atmosphere Research Initiative (SAFARI) which was implemented in its main campaign phase in 1992. SAFARI was the Eastern (African-borne) component of the Southern Tropical Atlantic Regional Experiment (STARE); the Western (South American/Transatlantic) component was realized as the Transport and Atmospheric Chemistry Near the Equator – Atlantic (TRACE-A) project. These projects were conducted under the scheme of the International Global Atmospheric Chemistry (IGAC) project which is a “core project” of the International Geosphere-Biosphere Programme (IGBP). One of the activities of IGAC Focus 2 (Natural Variability and Anthropogenic Perturbations of the Tropical Atmospheric Chemistry) investigates the impact of vegetation fires and biofuel burning on the global atmosphere and biosphere (Biomass Burning Experiment [BIBEX]). BIBEX has formally recognized AFARI-97 as an activity of IGBP-IGAC.
Background and Rationale
The observation of highly elevated levels of tropospheric ozone (O3) in some tropical regions, particularly over the southern tropical Atlantic Ocean between South America and Africa, led to the hypothesis that biomass burning emissions and subsequent photochemical processes may play an important role in atmospheric chemistry over a large region of the Earth. This was supported by spaceborne observations which showed the observed ozone enrichment to coincide geographically with regions of elevated carbon monoxide (CO) concentrations.
The Southern Tropical Atlantic Regional Experiment (STARE) was designed to investigate the chemical characteristics of the ozone-enriched airmasses over the southern tropical Atlantic and to study the sources of the trace gas emissions. Forest conversion burning in South America, especially in Brazil, and savanna fires in South America and Africa were identified as the most likely sources. Consequently, STARE was aimed at characterizing the emissions from plant biomass burning in the source regions on either side of the Atlantic, the transport of the air masses from these source regions to the atmosphere over the Atlantic, and the chemical transformations occurring in the air masses.
In this first intercontinental fire experiment, a total of 15 research institutions from 9 countries, supported by 4 additional countries, worked jointly on a single, but multi-facetted fire research project. The major field phase, an interdisciplinary international research campaign, took place in 1992. It took another four years to evaluate and publish the scientific results of the research program. Publications of the scientific results of TRACE-A and SAFARI are now available. A special issue of the Journal of Geophysical Research (American Geophysical Union) was published in October 1996 (1). On 811 pages, the special issue contains 60 articles written by 178 authors and co-authors, representing some 300 to 400 scientific and technical staff involved in the project. The results of this research programme are an impressing result of an unprecedented large international, interdisciplinary and intercontinental fire experiment.
The findings confirm the hypothesis that a large portion of the southern hemispheric atmosphere is subjected to dramatic seasonal changes influenced by vegetation fires. The transport meteorology of fire emissions has been clarified by SAFARI/TRACE-A. The implications of the STARE programme findings are manifold in regard to land use systems and sustainable development. The consequences of the research on the SAFARI (=African) side of STARE will be highlighted in a synthesis monograph which is dedicated to the ecology of fire in African savannas (corresponding to the results of SAFARI) and will be available in 1997 (2).
(1) TRACE-A and SAFARI Special Issue. Journal of Geophysical Research 101, No.D19, 23,519-24,330. (2) van Wilgen, B., M.O.Andreae, J.G. Goldammer, and J. Lindesay (eds.) 1997. Fire in Southern African savannas. Ecological and atmospheric perspectives. The University of Witwatersrand Press, 256 pp.
Whereas the atmospheric chemical importance of savanna and grassland fires in Southern Africa seem to be well understood, no information is available on atmospheric effects of fires occurring in East African savannas. Remotely sensed data reveal that extensive fires occur in the savanna areas of East Africa. Consequently it was decided to turn research attention to that part of the world. Special focus of the AFARI-97 project was the investigation of the relationship between aerosol production and associated CO and CO2 formation during prescribed experimental burns and wildfires of opportunity. The ecological value of these data is that aerosols formed during vegetation fires are assumed to be of significant importance for the radiation budget of the atmosphere on a global scale. The results will be used to improve the understanding of the aerosol sources and be added to the IGBP-IGAC and IGBP-DIS databases, i.e. they will be freely available to interested research parties.
Fig.1. Aerial view of a AFARI-97 experimental burning plot at Lewa Downs, Kenya, September 1997. Photo: J.G.Goldammer
AFARI-97 was conducted in two sites in Kenya in late September and early October 1997 (Lewa Downs Ranch in the Isiolo district immediately north of Mount Kenya and Hopcraft Ranch on the Athi Kapiti Plains 40 km south of Nairobi). The size of experimental burns ranged between 50-200 hectares. Ground measurements included standard botanical and fuel inventories (before and after the burns), fire behaviour, and meteorological data. The airborne component concentrated on aerosol sampling. Most of the experimental burns were coordinated with satellite measurements for validation purposes. The fires were described in detail on the ground and from small aircraft during the overpass of the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA weather satellite. In addition, it was tried to validate capabilities of the Space Shuttle Earth Observation System. The STS-86 mission, however, passed the burning sites at early morning hours and could not be coordinated with the experiments.
Participating institutions of AFARI-97
Max Planck Institute for Chemistry – Germany
University Nairobi – Kenya
National Academy of Sciences – Kenya
University Fort Hare – South Africa
Canadian Forest Service, Forest Fire Research – Canada
Division of Life Science, King’s College London – United Kingdom
Atmospheric Sciences Division, NASA Langley Research Center – U.S.A.
Department of Environmental Sciences, University of Virginia – U.S.A.
Principle contacts for AFARI-97:
Günter Helas / Johann G. Goldammer
Max Planck Institute for Chemistry Biogeochemistry Department PO Box 3060 D – 55020 Mainz GERMANY